1. Field of Invention
This invention relates to Mannich condensates prepared from an imidazole, formaldehyde and a polyalkylene polyamine, as hereafter defined. The Mannich condensates are useful, for example, as curing agents for epoxy resins.
More particularly, this invention relates to Mannich condensates prepared from starting materials including an imidazole and a polyalkylene polyamine. The imidazole and the polyalkylene polyamine are reacted with formaldehyde under Mannich condensation reaction conditions to provide the desired reaction product.
In accordance with the preferred embodiment of the present invention the polyamine that is reacted with the imidazole is a diamine and, in this situation, the invention may be illustrated by the following formula: ##STR3## Wherein: R represents hydrogen or a C.sub.1 -C.sub.4 alkyl group;
At least one of R' and R" represents hydrogen and the other represents hydrogen or methyl; PA0 n represents a number having an average value of 0 to about 100; PA0 Q represents --O-- or --NH--; and PA0 Z represents H or ##STR4## PA0 n represents a number having an average value of 0 to about 100, and PA0 at least one of R' and R" represents hydrogen and the other represents hydrogen or methyl.
2. Prior Art
The Mannich reaction is a well known reaction which has been extensively reviewed in the literature. See for example, "The Mannich Reaction", Org. Reactions 1, 303 (1942) and "Advances in the Chemistry of Mannich Bases", Methods in Synthetic Organic Chemistry-Synthesis, Academic Press, pgs. 703-775, 1973.
Shimp U.S. Pat. No. 4,417,010 is directed to a liquid curing agent for polyepoxides having terminal epoxide groups which is a liquid blend of a monoimidazole compound and an aliphatic polyol.
Kaufman U.S. Pat. No. 4,420,605 discloses a coating composition comprising a 1,2-epoxy resin, a modified imidazole catalyst and a polyfunctional reactant such as a polyhydric phenol, a polycarboxylic acid or dicyandiamide.